The incident occurred after Casemiro had dived into a late challenge on James Milner. The Liverpool midfielder was cleaned out by the tackle and ended up in the dugout as a result.
VAR checked the foul for a potential red card, although later decided not to take action. The Brazilian was booked on-field by the referee.
It was his third yellow card inside five days. The 30-year-old was sent off for two bookable offences inside a minute during El Clasico on Saturday.
Liverpool were incensed following Casemiro’s tackle on Milner. One man who squared up to him was Robertson, and the pair appeared to briefly exchange words.
In the back of the shot was Zidane. The Real Madrid manager was seen smiling during the exchange, which was quickly picked up on by fans on Twitter:
Zidane, of course, knows all about confrontation on the field. The Frenchman was famously sent off for headbutting Italy’s Marco Materazzi during the 2006 World Cup final – his last match before retirement.
Real continue their excellent form
It was another resilient display from both Zidane and Real. They progressed despite not being able to call upon the services of first-choice centre-back pairing Raphael Varane and Sergio Ramos.
Despite Liverpool having chances throughout the second leg, they could not turn them into goals.
The final scoreline of 0-0 was enough to see Real through, after a 3-1 victory in the first leg at the Bernabeu last week.
They are set to face Chelsea in the semi-final of the Champions League on April 28, with the second leg due to be played on May 4.
Zidane’s side are currently on a 15-game unbeaten run in all competitions, having not tasted defeat since a 2-1 LaLiga defeat to Levante at the end of January.
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